The transfer of liquids into and out of a storage or transfer container through the use of a controlled stream of air is known in the prior art. U.S. Pat. No. 3,319,578 Ware discloses a liquid transfer unit which has an adjustable venturi jet vacuum generator that is connected to a supply of compressed air. The venturi has a series of valves that can be set so as to create a negative pressure in an ancillary chamber communicating with a recovery tank whereby liquid will be drawn into the recovery tank; and that can also be set so as to create a positive pressure in the ancillary chamber whereby liquid can be pumped out of the recovery tank.
The recovery tank is provided with an inlet line for transferring the liquid from one container into the tank; and an outlet line for transferring the liquid from the tank to another container. The Ware transfer unit is a complex assembly, having five different valves; two separate transfer lines; a compound container; and is also cumbersome. The use of the compound container creates a problem because the level of the liquid in the recovery tank cannot be allowed to reach the level of the discharge line, or the level of the connection between the recovery tank and the ancillary chamber.
An assembly which operates in accordance with the general principals of the unit disclosed in the Ware patent would have utility in automotive garages for quickly and efficiently transferring radiator fluid, transmission fluid, oil, grease, and the like.
The unit disclosed in the Ware patent has very limited utility because of its size and its complexity. A simplified unit would also have utility in homes, and businesses other than garages.